I am trying to create my own attributes method called secure_attributes where I pass it an array of attributes and the minimum level the authorized user needs to be to view those attributes. I pass the current level of the authorized user as an instance_option. I'd like to extend the Serializer class so I can use this method in multiple serializers, but Im having issues.
This is what i have so far:
in config/initializers/secure_attributes.rb
module ActiveModel
class Serializer
def self.secure_attributes(attributes={}, minimum_level)
attributes.delete_if {|attr| attr == :attribute_name } unless has_access?(minimum_level)
attributes.each_with_object({}) do |name, hash|
unless self.class._fragmented
hash[name] = send(name)
else
hash[name] = self.class._fragmented.public_send(name)
end
end
end
end
end
and then in the individual serializer I have things like this:
secure_attributes([:id, :name, :password_hint], :guest)
and then
def has_access?(minimum_level=nil)
return false unless minimum_level
return true # based on a bunch of logic...
end
But obviously secure_attributes cannot see the has_access? method and if I put has_access inside the Serializer class, it cannot access the instance_options.
Any idea how I can accomplish what I need?
Maybe you want to do following - but I still do not get your real purpose, since you never did anything with the attributes but calling them:
module ActiveRecord
class JoshsSerializer < Serializer
class << self
def secure_attributes(attributes={}, minimum_level)
#secure_attributes = attributes
#minimum_level = minimum_level
end
attr_reader :minimum_level, :secure_attributes
end
def initialize(attr, options)
super attr, options
secure_attributes = self.class.secure_attributes.dup
secure_attributes.delete :attribute_name unless has_access?(self.class.minimum_level)
secure_attributes.each_with_object({}) do |name, hash|
if self.class._fragmented
hash[name] = self.class._fragmented.public_send(name)
else
hash[name] = send(name)
end
end
def has_access?(minimum_level=nil)
return false unless minimum_level
return true # based on a bunch of logic...
end
end
end
Related
I have a custom class in my application controller. Like below:
class Defaults
def initialize
#value_1 = "1234"
#value_2 = nil
#data = Data.new
end
end
class Data
def initialize
#data_1 = nil
end
end
Now in my controller method i have created an object of type Defaults
def updateDefaultValues
defaults = Defaults.new
# i am unable to update the value, it says undefined method
defaults.value_2 = Table.maximum("price")
defaults.data.data_1 = defaults.value_2 * 0.3
end
How to access value_2 from defaults object?
defaults.value_2
Also, how to access data_1 attribute from data object within defaults object?
defaults.data.data_1
You should use attr_accessor:
class Defaults
attr_accessor :value_1, :value_2, :data
# ...
end
defaults = Defaults.new
defaults.value_1 = 1
# => 1
defaults.value_1
# => 1
As you are using def as a keyword to define the method, that means def is a reserved keyword. You can't use reserved keywords as a variable.
You just need to rename your variable name from def to something_else and it should work! Your code will look like this:
def updateDefaultValues
obj = Defaults.new
obj.value_2 = Table.maximum("price")
obj.data.data_1
end
EDIT:
As per OP's comment & updated question, he had used def just as an example, here is the updated answer:
You may need attr_accessor to make attrs accessible:
class Defaults
attr_accessor :value_1, :value_2, :data
...
...
end
class Data
attr_accessor :data_1
...
...
end
Add value_2 method in Defaults class
class Defaults
def initialize
#value_1 = "1234"
#value_2 = nil
#data = Data.new
end
def value_2
#value_2
end
end
class Data
def initialize
#data_1 = nil
end
end
We are trying to load fixtures for a group of models that uses a different database connection than ActiveRecord::Base (inheriting from Foo::Base in this example).
We've created this module that we include in ActiveSupport::TestCase and the specify a path to the .yml files and e.g. foo_fitures :all. This works great for the first test that runs. Fixture accessors are defined and records are found in the database. But for subsequent tests there are no records in the database.
module Foo::Fixtures
extend ActiveSupport::Concern
included do
setup :setup_foo_fixtures
teardown :teardown_foo_fixtures
class_attribute :foo_fixture_path
class_attribute :foo_fixture_table_names
self.foo_fixture_table_names = []
end
module ClassMethods
def foo_fixtures(*fixture_names)
if fixture_names.first == :all
fixture_names = Dir[foo_fixture_path.join("**/*.yml")].map { |f| File.basename(f, ".yml") }
else
fixture_names = fixture_names.flatten.map { |n| n.to_s }
end
self.foo_fixture_table_names |= fixture_names
require_fixture_classes(fixture_names)
setup_fixture_accessors(fixture_names)
end
end
def setup_foo_fixtures
#loaded_fixtures.merge!(load_foo_fixtures)
end
def teardown_foo_fixtures
Foo::Base.clear_active_connections!
end
private
def load_foo_fixtures
foo_classes = Foo::Base.subclasses.flat_map { |klass| klass.abstract_class ? klass.subclasses : klass }
class_names = foo_classes.each_with_object({}) do |klass, memo|
memo[klass.table_name.to_sym] = klass if klass.table_name.present? && foo_fixture_table_names.include?(klass.table_name)
end
foo_fixtures = ActiveRecord::Fixtures.create_fixtures(foo_fixture_path, foo_fixture_table_names, class_names) do
Foo::Base.connection
end
Hash[foo_fixtures.map { |f| [f.name, f] }]
end
end
Rails' fixture system is a bit convoluted, and I'm not able to figure out what we are missing to make sure that our extra fixtures are loaded.
OK. It looks like it might be the transactions that are removing our fixtures from the database. My guess is that the transaction has started before our code loads in the fixtures, so that's why they are there for the first test, but gone at the second.
So we changed strategy, and now we just hook into load_fixtures and fixtures. This works just fine.
module FooFixtures
module ClassMethods
def foo_fixture_classes
collect_subclasses = ->(k) { k.abstract_class ? k.subclasses.flat_map(&collect_subclasses) : k }
Foo::Base.subclasses.flat_map(&collect_subclasses)
end
def foo_fixture_path
Rails.root.join("test/foo_fixtures")
end
def foo_fixture_table_names
Dir[foo_fixture_path.join("**/*.yml")].map { |f| File.basename(f, ".yml") }
end
def fixtures(*fixture_names)
super
if fixture_names.first == :all
require_fixture_classes(foo_fixture_table_names)
setup_fixture_accessors(foo_fixture_table_names)
end
end
end
private
def load_fixtures
foo_fixture_path = self.class.foo_fixture_path
foo_fixture_table_names = self.class.foo_fixture_table_names
class_names = self.class.foo_fixture_classes.each_with_object({}) do |klass, memo|
memo[klass.table_name.to_sym] = klass if klass.table_name.present? && foo_fixture_table_names.include?(klass.table_name)
end
foo_fixtures = ActiveRecord::Fixtures.create_fixtures(foo_fixture_path, foo_fixture_table_names, class_names) do
Foo::Base.connection
end
super.merge(Hash[foo_fixtures.map { |f| [f.name, f] }])
end
end
class ActiveSupport::TestCase
extend FooFixtures::ClassMethods
prepend FooFixtures
self.foo_fixture_classes.each do |fixture_class|
set_fixture_class fixture_class.table_name.to_sym => fixture_class
end
...
end
In activerecord, attribute setters seems to be called in order of the param hash.
Therefore, in the following sample, "par_prio" will be empty in "par1" setter.
class MyModel < ActiveRecord::Base
def par1=(value)
Rails.logger.info("second param: #{self.par_prio}")
super(value)
end
end
MyModel.new({ :par1 => 'bla', :par_prio => 'bouh' })
Is there any way to simply define an order on attributes in the model ?
NOTE: I have a solution, but not "generic", by overriding the initialize method on "MyModel":
def initialize(attributes = {}, options = {})
if attributes[:par_prio]
value = attributes.delete(:par_prio)
attributes = { :par_prio => value }.merge(attributes)
end
super(attributes, options)
end
Moreover, it does not works if par_prio is another model that has a relation on, and is used to build MyModel:
class ParPrio < ActiveRecord::Base
has_many my_models
end
par_prio = ParPrio.create
par_prio.my_models.build(:par1 => 'blah')
The par_prio param will not be available in the initialize override.
Override assign_attributes on the specific model where you need the assignments to happen in a specific order:
attr_accessor :first_attr # Attr that needs to be assigned first
attr_accessor :second_attr # Attr that needs to be assigned second
def assign_attributes(new_attributes, options = {})
sorted_new_attributes = new_attributes.with_indifferent_access
if sorted_new_attributes.has_key?(:second_attr)
first_attr_val = sorted_new_attributes.delete :first_attr
raise ArgumentError.new('YourModel#assign_attributes :: second_attr assigned without first_attr') unless first_attr_val.present?
new_attributes = Hash[:first_attr, first_attr_val].merge(sorted_new_attributes)
end
super(new_attributes, options = {})
end
I have a concern allowing me to give the back end user the ability to sort elements. I use it for a few different elements. The rails community seems to be pretty vocal against concern and callbacks, i'd like to have a few pointers on how to better model the following code :
require 'active_support/concern'
module Rankable
extend ActiveSupport::Concern
included do
validates :row_order, :presence => true
scope :next_rank, lambda { |rank| where('row_order > ?',rank).order("row_order asc").limit(1)}
scope :previous_rank, lambda { |rank| where('row_order < ?',rank).order("row_order desc").limit(1)}
scope :bigger_rank, order("row_order desc").limit('1')
before_validation :assign_rank
end
def invert(target)
a = self.row_order
b = target.row_order
self.row_order = target.row_order
target.row_order = a
if self.save
if target.save
true
else
self.row_order = a
self.save
false
end
else
false
end
end
def increase_rank
return false unless self.next_rank.first && self.invert(self.next_rank.first)
end
def decrease_rank
return false unless self.previous_rank.first && self.invert(self.previous_rank.first)
end
private
def assign_default_rank
if !self.row_order
if self.class.bigger_rank.first
self.row_order = self.class.bigger_rank.first.row_order + 1
else
self.row_order=0
end
end
end
end
I think a Concern is a good choice for what you are trying to accomplish (particularly with validations and scopes because ActiveRecord does those two very well). However, if you did want to move things out of the Concern, apart from validations and scopes, here is a possibility. Just looking at the code it seems like you have a concept of rank which is represented by an integer but can become it's own object:
class Rank
def initialize(rankable)
#rankable = rankable
#klass = rankable.class
end
def number
#rankable.row_order
end
def increase
next_rank ? RankableInversionService.call(#rankable, next_rank) : false
end
def decrease
previous_rank ? RankableInversionService.call(#rankable, previous_rank) : false
end
private
def next_rank
#next_rank ||= #klass.next_rank.first
end
def previous_rank
#previous_rank ||= #klass.previous_rank.first
end
end
To extract out the #invert method we could create a RankableInversionService (referenced above):
class RankableInversionService
def self.call(rankable, other)
new(rankable, other).call
end
def initialize(rankable, other)
#rankable = rankable
#other = other
#original_rankable_rank = rankable.rank
#original_other_rank = other.rank
end
def call
#rankable.rank = #other.rank
#other.rank = #rankable.rank
if #rankable.save && #other.save
true
else
#rankable.rank = #original_rankable_rank
#other.rank = #original_other_rank
#rankable.save
#other.save
false
end
end
end
To extract out the callback you could have a RankableUpdateService which will assign the default rank prior to saving the object:
class RankableUpdateService
def self.call(rankable)
new(rankable).call
end
def initialize(rankable)
#rankable = rankable
#klass = rankable.class
end
def call
#rankable.rank = bigger_rank unless #rankable.ranked?
#rankable.save
end
private
def bigger_rank
#bigger_rank ||= #klass.bigger_rank.first.try(:rank)
end
end
Now you concern becomes:
module Rankable
extend ActiveSupport::Concern
included do
# validations
# scopes
end
def rank
#rank ||= Rank.new(self)
end
def rank=(rank)
self.row_order = rank.number; #rank = rank
end
def ranked?
rank.number.present?
end
end
I'm sure there are issues with this code if you use it as is, but you get the concept. Overall I think the only thing that might be good to do here is extracting out a Rank object, other than that it might be too much complexity that the concern encapsulates pretty nicely.
I use a lot of iterations to define convenience methods in my models, stuff like:
PET_NAMES.each do |pn|
define_method(pn) do
...
...
end
but I've never been able to dynamically define setter methods, ie:
def pet_name=(name)
...
end
using define_method like so:
define_method("pet_name=(name)") do
...
end
Any ideas? Thanks in advance.
Here's a fairly full example of using define_method in a module that you use to extend your class:
module VerboseSetter
def make_verbose_setter(*names)
names.each do |name|
define_method("#{name}=") do |val|
puts "##{name} was set to #{val}"
instance_variable_set("##{name}", val)
end
end
end
end
class Foo
extend VerboseSetter
make_verbose_setter :bar, :quux
end
f = Foo.new
f.bar = 5
f.quux = 10
Output:
#bar was set to 5
#quux was set to 10
You were close, but you don't want to include the argument of the method inside the arguments of your call to define_method. The arguments go in the block you pass to define_method.
Shoertly if you need it inside one class/module:
I use hash but you can put there array of elements etc.
PETS = {
"cat" => "meyow",
"cow" => "moo",
"dog" => "ruff"
}
def do_smth1(v)
...
end
def do_smth(sound,v)
...
end
#getter
PETS.each{ |k,v| define_method(k){ do_smth1(v) } }
#setter
PETS.each{ |k,v| define_method("#{k}="){|sound| do_smth2(sound, v) }